I am not sure it I saw this on Modern Marvles or something on Disc channel but it was the beam powered propulsion system. These guys had a high powered laser and did one test where they shot the beam at a block of graphite and from the looks of it produced about a 2" square burn on it (I think it was a calibration or some other test.

Then they had a rod about 10' tall probably 1/2" diameter and had the beam pointed straight up along the rod. They had a flared piece of SST or Aluminum (kinda looked like a trumpet horn but it came to a point with a hole in the center. The slid the funnel down over the rod and spun the funnel with compressed air, then they fired off the laser and if sounded like some one shooting a machine gun and the thing took off up to about 100'. It seems like it was a while ago (I think even before laser diodes were around) . I don't remember if the show was on space travel or lasers, but it was amazing to me to see a result like that with just light.

Jeff

I just saw on TV a concentrated sun reflector array... they pointed it at a piece of 1/4" sheet steel, it was no more than 3 secs and it melted right threw! It looked like a 15 foot reflector.